Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Covalent modification and crosslinking of carbon materials by sulfur addition

Inactive Publication Date: 2014-05-22
RICE UNIV
View PDF15 Cites 16 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present patent text describes methods of forming cross-linked carbon materials by associating a sulfur source with carbon materials and initiating a chemical reaction through which covalent linkages are formed between the carbon materials. The carbon materials can include non-polymeric carbon materials such as carbon nanotubes, carbon fibers, and graphene. The sulfur source can include elemental sulfur, oligomeric sulfur, and various other sulfur compounds. The chemical reaction can occur in the absence of solvents and surfactants and can be initiated by heating. The resulting cross-linked carbon materials have covalent linkages between the carbon materials, which can include sulfur bridges, and can also contain dopants such as iodine, chlorine, bromine, and combinations thereof.

Problems solved by technology

Current methods of forming aggregated or bundled carbon materials suffer from numerous limitations, including lack of efficacy, stringent reaction conditions, and inconsistent results.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Covalent modification and crosslinking of carbon materials by sulfur addition
  • Covalent modification and crosslinking of carbon materials by sulfur addition
  • Covalent modification and crosslinking of carbon materials by sulfur addition

Examples

Experimental program
Comparison scheme
Effect test

example 1

Solvent-Free Vulcanization of Carbon Nanotube Fibers for Physical Property Improvement

[0068]In this Example, Applicants present a facile method for improvement of the physical properties of carbon nanotube (CNT) fibers. Highly aligned CNT fibers produced via wet spinning were subjected to solvent-free sulfur vulcanization / crosslinking resulting in increased tensile strength and elastic modulus, although electrical conductivity was hampered. Addition of iodine dopant, either concurrent with crosslinking or in an additional step, led to significant improvement in electrical conductivities with no loss in mechanical properties. CNT crosslinking was characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, and effective solubility. Because this crosslinking process is applied to pre-formed fibers, this method is expected to be applicable to CNT / graphene materials created by any process.

[0069]In this Example, Applicants relied on sulfur vulcanization to cross-link CNT fibers...

example 1.1

Materials and Methods

[0080]CNT fibers were manufactured by a reported method (Science, 2013, 339, 182-186) using CNTs (purified grade) purchased from Continental Carbon Nanotechnologies Inc. (Houston, Tex.). Because of variability in fiber batches, all results are normalized to the unprocessed fiber properties from which they derived. All other chemicals were purchased from Sigma Aldrich and used without further purification. Raman spectra of CNT materials were measured using a Renishaw InVia Raman Confocal Raman microscope, with excitation wavelengths of 514, 633, and 785 nm. Scanning electron microscopy (SEM, FEI Quanta 400 ESEM FEG) was used to determine the diameter of the CNT fibers at a magnification of ˜104 for a minimum of 4 segments of a 10-20 mm length of fiber. Mechanical testing of CNT fiber was performed on an Instron model 1000 testing frame with a 5 kg load cell as reported previously.

[0081]The CNT foam was produced by a method to be reported from the same CNT source ...

example 1.2

Protocol for Sulfur Crosslinking

[0082]A length of CNT fiber was attached to a glass support rod by evaporation of a drop of 50% (w / w) sodium silicate solution in water, as a temperature stable and unreactive glue. The other end of the fiber was attached in the same fashion to a glass weight (˜100 mg) to provide tension on the fiber. The glass rod and fiber were added to a glass reaction tube loaded with DTBT (3 mg, 9 μmol). This reactor was fitted with a vacuum adapter sealed with copious vacuum grease. The reaction vessel was evacuated for five minutes and then sealed. The reactor was added upright (taking caution to ensure the fiber was hanging freely and under full tension from the glass weight) to an oven set at 200° C. The reactor was removed after 20 hours, after which the fiber was removed from the reactor, washed with a stream of acetone, and its resistance was measured by four-point probe. Mechanical analysis was performed as described (Science, 2013, 339, 182-186) to deter...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

In some embodiments, the present disclosure pertains to methods of forming cross-linked carbon materials by: (a) associating a sulfur source with carbon materials, where the sulfur source comprises sulfur atoms; and (b) initiating a chemical reaction, where the chemical reaction leads to the formation of covalent linkages between the carbon materials. In some embodiments, the covalent linkages between the carbon materials comprise covalent bonds between sulfur atoms of the sulfur source and carbon atoms of the carbon materials. In some embodiments, the chemical reactions occur in the absence of solvents while carbon materials are immobilized in solid state. In some embodiments, the carbon materials include carbon nanotube fibers. In some embodiments, the methods of the present disclosure also include a step of doping carbon materials with a dopant, such as iodine. Further embodiments of the present disclosure pertain to cross-linked carbon materials formed in accordance with the above methods.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Patent Application No. 61 / 723,875, filed on Nov. 8, 2012. The entirety of the aforementioned application is incorporated herein by reference.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH[0002]This invention was made with government support under Air Force Office of Scientific Research Grant No. FA9550-12-1-0035, awarded by the U.S. Department of Defense. The Government has certain rights in the invention.BACKGROUND[0003]Current methods of forming aggregated or bundled carbon materials suffer from numerous limitations, including lack of efficacy, stringent reaction conditions, and inconsistent results. Therefore, a need exists for more effective methods of forming various types of carbon materials in aggregated or bundled forms.BRIEF SUMMARY[0004]In some embodiments, the present disclosure pertains to methods of forming cross-linked carbon materials. In some embodiments, such methods ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C01B31/02B01J19/12H01B1/04
CPCC01B32/168H01B1/04
Inventor PASQUALI, MATTEOWHITING, BRYAN THOMAS
Owner RICE UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com